Trends in Antarctic Snowmelt Onset for the Period 1988 to 2008 from Passive Microwave Data

Onset dates of annual snowmelt on the Antarctic sea ice are available from 1988 to 2008. These data sets, derived from passive microwave brightness temperature, provide knowledge about the ice and snow surface conditions during summer melting. In the context of ongoing climate research, such data sets help establish connections between melt signals and changes in meteorological boundary conditions while also enabling the identification of potential trends in snowmelt patterns in relation to other evolving climate indicators. Interannual variability in the austral melt onset, a 20-year trend, and its relationship with atmospheric indices such as the Southern Oscillation Index and the Multivariate El Niño/Southern Oscillation Index are discussed in this exploratory study through the observations made using these data sets. A slight shift towards delayed melt onset is observed, though this is not statistically significant. However, certain areas, such as the eastern Weddell Sea, Ross Sea, and Bellingshausen Sea, demonstrate notable trends. Furthermore, the Southern Hemisphere Annular Mode (SAM) index correlates significantly with the melt onset dates in various sectors of Antarctica and latitudinal zones, indicating the effect of changes in the westerly winds that encircle Antarctica.